1. Field of the Invention
The present invention relates to an image forming apparatus wherein an electronic photography system is used, such as a copier, a printer, a facsimile and a machine wherein these are combined, and, in particular, to an image forming apparatus that can obtain the reproduction of an image by using a specific developing material in addition to the reproduction of an image by using a common developing material.
2. Description of the Related Art
Conventional image forming apparatuses such as a copier, a printer and the like wherein an electronic photography system or an electro static transfer system are utilized is widely known. In such image forming apparatuses, normally a monochromatic image obtained by means of a black toner, a full color image obtained by means of color toners of yellow, cyan and magenta, respectively, or the like, are formed on a sheet of paper which is then outputted. In addition to these conventional (two-dimensional) images, a technology for obtaining a three-dimensional image using a specific toner (foaming toner) has been proposed. The present applicant has previously proposed, for example, “Image Formation Toner, Manufacturing Method for the Same and Method for Forming Three-Dimensional Images Using the Same as well as Image forming apparatus” and “Image forming apparatus” in Japanese Unexamined Patent Publication No. 2000-131875, in Japanese Unexamined Patent Publication No. 2001-194846, and the like. Furthermore, a conventional technology for obtaining an image of metallic colors, such as of gold or of silver, by using specific toners (metallic color toners) has been proposed.
However, it is not appropriate for all image forming apparatuses to be provided with the function of being able to form images using specific toners (foaming toners or metallic color toners) because it forces the user who does not need an image obtained by means of specific toners to pay additional costs for additional functions. On the other hand, it is in efficient to separately manufacture image forming apparatuses that solely use conventional toners and image forming apparatuses that use specific toners as well as conventional toners. Therefore, image forming apparatuses that solely use conventional toners are equipped, as an option, with a developing unit and an image forming unit that use specific toners and, thereby, it is considered that image forming apparatuses that meet the needs of the user can be efficiently provided.
On the other hand, in some cases, wherein an image forming apparatus is formed so that a developing unit and an image forming unit can be equipped (in a replaceable manner or in an additive manner) with the image forming apparatus in the above described manner, the user may mistakenly instruct the formation of an image that corresponds to a developing unit, or the like, that is not installed. In such a case, if an announcement is not made, the user cannot recognize that the corresponding developing unit, or the like, is not installed.